Copying sheet, method of making and using same



COPYING SHEET, METHOD OF MAKING AND USING SAME Filed July 7. 1954 Sept. 30, 1958 e. c. PH'ILLPOTTS 2 Sheets-Sheet 1 0. 6 S M S T 8 6 I 0 C 4 C I I T I? a a a a m o 68 t! 0 f 0 I p 08 f C r f C e L 0h 0. U U 8 8 Cr L fs S e S P u le 1. W H k U L." q W 8 a C q C P 0 fl rm w v M: a m n. ma V1 6P 0 m 0 M R W w W m I k. m m .w C 0 R 04! "0E 0 T Pi W E l Ww IG I 0 Black surface Whife paper White paper 40 Wax oil coating Protective laye paper and wax av W 1 yam/I A ';TORNEIS.'

Sept. 30, 1958 I G. c. PHILLPOTTS 2,854,350

COPYING SHEET, METHOD OF MAKING AND USING SAME Filed July 7, 1954 2 Sheets-Sheet 2 FIG. 5

PAPER WHITE [COLORED SURFACE COLORED OILY NON-OILY COATING COATING \M/' I i OIL SURFACE IMPERVIOUS COATING COATING OIL IMPERVIOUS COATING i I I OILY COATING INVENTOR PRODUCT Gfoeef 60/601597 )DH/ALP07'7'6 ATTORNEY United States Patent COPYING SHEET, METHOD OF MAKING AND USING SAME George Cordery Phillpotts, Kingston Hill, England, as-

signor to Caribonum Limited, London, England, a British company Application July 7, 1954, Serial No. 441,739

Claims priority, application Great Britain July 21, 1953 14 Claims. (CL 117-36) The present invention is concerned with the production of written or typewritten matter in a manner which lends itself to the production of a number of copies in a very simple manner.

Hitherto, for the purpose of producing copies of handwritten or typewritten matter, it has been customary for many years past to use a sheet of paper coated with a transfer composition, the so-called carbon paper, which I is interposed between the paper upon which the copy is to be taken and the original, that is to say the sheet which will receive the hand-written matter or the matter produced by direct contact with the type face of the typewriter through a typewriter ribbon. It is, of course, understood that if two or more copies are required, a similar number of sheets of carbon paper and of copy paper will be used.

While carbon paper gives on -the whole satisfactory work, it must by its very nature be dirty, and when it has been typed upon, the effect is to raise the characters on the face of the carbon paper in such a Way that in certain circumstances they can be transferred to the next sheet of paper upon which it is desired to make a copy. This is undesirable.

In order to overcome these objections, various proposals have been made, though none of them is entirely satisfactory. For example, in one suggestion a paper with a coloured surface masked by a friable white composition has been proposed. In this the active surface is presented face towards the type of typewriter underneath an overlying sheet of paper (the original) and when typed upon, the white coating on the active surface is removed by the overlying sheet, so that the coloured surface shows through in contrast to the bulk of the white coating which remains. Such a surface is very easily damaged and the subject-matter and copy easily erased.

.It has also been proposed to employ a sheet of paper impregnated with an active ingredient as, for example, tannic acid and another sheet of paper impregnated with another active ingredient, as, for example, ferrous sulphate, and upon the two being brought together and typed upon, combination of the two active ingredients takes place immediately under the type, producing a coloured effect in contrast to the surrounding paper and thereby providing a readable copy. This has the disadvantage that the activity or otherwise of the sheets tends to vary with the atmospheric conditions, since it is necessary to include a humidifying ingredient in order to ensure that the reacting materials are sufiiciently moist to Work; the coatings on the paper are thus very susceptible to weather conditions, that is to say, they are likely to be more active on a damp day than on a dry day, and furthermore, it is necessary to use two kinds ofpaper and to ensure that they are correctly placed, reacting face to reacting face.

Other developments of this kind have been proposed in which the active ingredient is a colourless form of an aniline dye which developsits colour when it is brought into contact with an activating substance. The objections to these are that such reproducing papers are difficult to produce, costly to manufacture, and do not have any great permanence owing to the fugitive nature of the aniline dyes used.

The object of the invention is to overcome these various difliculties in a simple manner and produce an alternative to carbon paper which does not involve counteracting disadvantages. As contemplated by the present invention, no material which, in the ordinary sense, react, are used at all, nor are the materials coloured, with the exception of the base paper, and for this purpose the base paper may be coloured in any way that is suitable and the dye or colouring material may be chosen without any special limitations so as to ensure permanence. The base paper is preferably coloured on one face, i. e. the active face, only.

According to one aspect of the invention, sheet material suitable for receiving and displaying written matter comprises paper having a surface coloured other than white upon which is applied an adherent, opaque coating of contrasting colour comprising finely-divided calcium carbonate.

According to another aspect of the invention, sheet material suitable for receiving and displaying written matter comprises oil-impervious paper having a coloured surface upon which is applied an adherent,;substantially white, opaque coating comprising finely-divided calcium carbonate and having an oily substance of approximately the same refractive index as the opaque coating applied to the reverse surface.

According to a further aspect of the invention, sheet material suitable for receiving and displaying written matter comprises paper having a coloured surface, an adherent, substantially white, opaque coating-comprising finely-divided precipitated calcium carbonate dispersed in a binder selected from the group consisting-of sodium alginate, gum arabic and adhesive cellulose derivatives applied to the coloured surface of the paper, an oil-impervious protective layer applied to the reverse surface of the paper and an oily substance selected from the group consisting of oils, petroleum jelly, oils modified with a wax and oils modified with petroleum jelly applied to the oil-impervious layer, said oily substance having a refractive index substantially the same as that of the opaque coating.

A process in accordance with the invention for manufacturing sheet material suitable for receiving and displaying written matter comprises thesteps of providing paper with a surface which is coloured other than white, and applying over the coloured surface an adherent opaque coating. of contrasting colour comprising finelydivided calcium carbonate.

The invention also consists in a process for producing written matter on sheet material comprising paper having a coloured surface, which comprises masking the coloured surface with an adherent, substantially white opaque coating comprising precipitated calcium carbonate and applying an oily substance to selected portions of the opaque coating to render the coating transparent and allow the colour of the coloured surface to appear in the form of written matter.

In carrying out the invention, calcium carbonate in the form of a very finely precipitated powder is mixed with a suitable binder, for example, a solution of sodium alginate or gum arabic, and is then coated upo n one surface of a sheet of white (or tinted) paper which has had one or both surfaces suitably coloured, as by coating or printing or any other known process, .or coloured paper may be used if desired. It ispreferable that the coloured surface should be fast to light and am a--suitablegrairfsothat the subsequent coating operation willensurethe adhesion-of the coating composition. For this purpose-the surface of the paper may be stained by suitable aniline dyes, preferably those not soluble -in water,'e. -g.jspifitnigrosine, soluble in, for '-exa'mple, methylated spirit,'-or'some other solvent, and lhe ink-so prepared by dissolving the dye in a suitable -'solvent'may be printed on to the paper or coated on by rollers and a doctor blade or by any other suitable method. An inkcontaining pigments such as carbon 'black' and a'binder su'ch'as'a shellac soap or other suitable-material may-replace the spirit solution of aniline "dye. A suspension of carbon black in a solution oi ethyl cellulose or othersuitable plastic material is very -useful,' since this -'-acts as a barrier to the oily coating on therear face ofthepaper. 'The colouring materials need not be limited to pigment dyes since they may also be prep'ared from suitable mineral colours as, for exa'mple, carbon black, dark brown earths such as the darker coloured o'chres, chrome-green, bronze blue and suitable lake colours as, for example, the very light-fast tungsten *lttkesof'methylviolet and other-triphenylmethane or related dyes, though any suitable dye-stufi lake may be use'd; It is'only necessary to ensure that these colours are so coated on'the paper that they do not penetrate through to the .back and'that the surface which they leave after staining the surface of the paper, is not fgreasy-in any way so as to interfere with the final coatmug,

Thefinal coating may consist of a smooth, even, thin coating of a suspension of calcium carbonate in a water solu'tion of sodium alginateor other suitable binder and this'ma'y,-in sutficient quantity to give a white appearance to the sheet,'be applied to the coloured side of the paper by any suitable means as, for example, by a printing processyby rotogravure, by means of rollers and doctor blades or by any other suitable method.

The-coating so applied is allowed to dry. If this coating isnow .typed upon with a typewriter ribbon contain- =ing no other ingredient than an oil or a suitable oily material=the points at which the typewriter type faces :drive the ribbon into'contact with the white surface of --thei composite paper become immediately black (or other lcolour, according to the base colour) due to the calcium (carbonate becoming transparent-as'explaine'd above. In this'way a good readable copy is obtained.

iIt is not essential to use oils alone, and oils which have -beenmodified with waxes or petroleum jelly fora variety tofiotherpurposes may be suitable. Petroleum jelly itself is an admirable producer of transparency in the calcium carbonate'coating-and' the same, in certain circumstances; can be said of waxes, particularly when they tareused to bind. small quantities of oil.

If the'paper referred to above as being coated on one side with theaniline dye or other colour is also -coated upon the other side'with a substance calculated to prevent the passage through the paper of oils or other 1 greasy substances,then this'protected reverse side of the paper may be coated with a very thin coating .of, for example, paraffin wax'containing a little oil or suitable oily substance or with mixture of paraffin wax and petroleum jelly or with a very thin coating of petroleum jelly alone. If now the oily side of the paper is placed -in contact with the calcium carbonate-coated face of another sheet, inserted in the typewriter and typed upon, the small quantity of oil transferred from .the paper to --the carbonate will produce agood readable copy.

-Thus itwill be seen that as. far .asthe userv is concerned, no transferable colour whatever is involved in "handling this copying paper, that is to say no colour which could be transferred to the fingers or clothes of the user in the same-way-1that ordinary carbon, paper could be transferred to .the fingers or clothes. This .isva very great advantage.

. A. further advantage is that ifs-the. original .is made embodiment neitherribbon nor carbon paper is required on the typewriter and writing-may be etfected merely' by also from the prepared paper a colourless typewriter ribbon inked only-with oil, oils and waxes or oily sub- -is made 'is, comparatively speaking, insensitive tuntil brought into contact with oil or oily materials. With regard to the latter, quite good results can be obtained with some materials which are not strictly oils in the ordinary sense of the word, as'for example, the so-called plasticisers normallyusedfor softening plastic substances, e. g. tricresyl phosphate, dimethyl phthalate, etc. These may be bound with suitable waxes if desired. An advantage of some of these substances, e. g. tricresyl phosphates, is that they have very low vapour pressures and do not tend to dry.

Another embodiment of this invention, which avoids the necessity for a preliminary coating of the base paper with a colouring material on the surface, is that the calcium carbonate may be mixed with a comparatively small quantity, some 10% or less, of the colour it is desired to develop. The mixture of'calcium carbonate and colour is then suspended in a solution of sodium alginate or other suitable binder, as above, and coated directly on to white (or coloured) paper. When dry, the coating assumes a pale pastel shade of the colour used, or-a grey in the case of black. On bringing oily materials into contact with the surface, as indicated above, the calcium carbonate is rendered transparent and the colouring material shows up in contrast to the surrounding paste] or grey shade.

In another embodiment of this invention, the base paper may first be coloured on one side as set out above or'coloured paper may be used. On this coloured surface a thin layer consisting of an oil or oily substance .bound'by wax or other'suitable binder is applied and over this a protective layer is formed by coating on a thin film of a water soluble cellulose derivate, e. g; methyl cellulose. Alternatively the oily substance may be in the form of minute discrete particles bound with a binder When this is applied to the mother suitable binder. 'On striking this with the type- -writer head, the protective layer is ruptured and-the oilymedium provides the' desired contrast when it comes into contact with' the calcium carbonatelayer. In this the pressure of a' stylus.

In order that the invention may be readily understood, several embodiments thereof are described below inconjunction with the accompanying drawing.

In the drawing,

Figs-1 to 4 illustrate diagrammatically four difierent 'forms of paperin accordance with this invention.

Fig. 5 is a flow sheet of the process of this invention. Referring to Figl, a sheet of white paper isindicated at 10 which has its upper surface 11 stained black by the application of a solution in methylated spirit of a black .anilinedyestufi. Upon this black surface 11 isapplied a white opaque coating 12 consisting .of precipitated calcium carbonate bound with an aqueous solution of sodium alginate. Black writing can be produced on .this

paper byusing it in a typewriter. -having its. ribbon impregnated with; an; oilnimtead; of: with; an ink, .the oil having'a refractive index approximately that of calcium carbonate.

Referring to Fig. 2, the sheet of paper is similar to that illustrated in Fig. 1 in having a black surface 11 to which an opaque coating 12 is applied. The reverse surface of the paper 10 is provided with a thin coating 13 of paraflin wax containing a little oil, which coating has approximately the same refractive index as calcium carbonate. If two or more sheets of this paper are arranged with their wax coatings 13 in contrast with the opaque coatings 12 of underlying sheets and the sheets are placed in a typewriter, the top sheet can be typed upon to produce an original by using an inked ribbon in the customary manner and the underlying sheet or sheets will provide copies in black writing, produced by the wax coating 13 of each sheet rendering transparent the opaque coating 12 of the underlying sheet.

Fig. 3 illustrates an embodiment designed for use in a manner similar to that shown in Fig. 2. The sheet of paper 10 has a black surface 11 on which the opaque coating 12 is applied. The paper also carries a wax coating 13a on its underside to act upon the opaque coating 12 of an underlying sheet, but this wax coating 13a is provided upon an intermediate protective layer 14 serving to prevent the wax coating 13:: penetrating the paper 10 and damaging the opaque coating 12.

Referring to Fig. 4 the sheet of paper 10 there shown is provided with the aforementioned black surface 11. Upon this is applied a coating 15 of an oily substance which in turn is coated with a protective layer 16 obtained by applying aqueous solution of methyl cellulose. The opaque coating 12 has approximately the same refractive index as the coating 15 and is provided upon the protective layer 16. Paper of this kind may be used as a single sheet or in a stack for producing an original and several copies simultaneously. In either case, writing may be produced on the paper by the use of a stylus or by typing on the paper without using a ribbon of any kind. The local pressure applied in writing or typing ruptures the protective layer 16 and allows the oily coating 15 to make the opaque coating 12 transparent to cause the colour of the black surface 11 to appear.

Letter headings or the like may also be printed, if desired, on paper prepared according to the invention either with an ordinary printing ink or even with no more than an oily material. In the case of printing, it is advantageous to use an ordinary uncoloured printing ink varnish, since this gives the desired resu1tsvery sharp outlines and satisfactory fixation.

I claim:

1. Sheet material suitable for receiving and displaying written matter which comprises oil-impervious paper having a coloured surface upon Which is applied an adherent, substantially white, opaque coating comprising finely-divided calcium carbonate in a form which is adapted to be rendered transparent thereby to allow the color of the paper surface to appear by the application to selected portions of the opaque coating of an oily substance having of sodium alginate, gum arabic and adhesive cellulose derivatives applied to the coloured surface of the paper,

said calcium carbonate coating being in a form which is adapted to be rendered transparent thereby to allow the color of the paper surface to appear by the application to selected portions of the opaque coating of an oily substance having approximately the same refractive index .as calcium carbonate, an oil-impervious protective layer 6 applied to the reverse surface of the paper and an oily substance selected from the group consisting of oils, petroleum jelly, oils modified with a wax and oils modified with petroleum jelly applied to the oil-impervious layer, said oily substance having a refractive index substantially the same as that of the opaque coating.

3. Sheet material as claimed in claim 1 in which the opaque coating comprises finely-divided precipitated calcium carbonate dispersed in a binder selected from the group consisting of sodium alginate, gum arabic and adhesive cellulose derivatives.

4. Sheet material as claimed in claim 1 in which the opaque coating comprising calcium carbonate includes a small quantity of a substance having the colour of the desired writing.

5. Sheet material suitable for receiving and displaying written matter which comprises paper having a coloured surface, a coating of an oily substance applied to the coloured surface, said oily substance having approximately the same refractive index as precipitated calcium carbonate, an oil-impervious protective layer provided over said coating of oily substance and an adherent, substantially white opaque coating comprising finely-divided precipitated calcium carbonate provided over said oil-impervious protective layer, said oil-impervious protective layer being adapted to rupture locally under pressure applied to the sheet material by the action of writing thereon so as to permit the oily substance to render the opaque coating locally transparent and thereby allow the colored surface to appear.

6. Sheet material suitable for receiving and displaying written matter which comprises paper having a surface coloured other than white, a non-oily coating comprising discrete particles of an oily substance dispersed in a binder applied to the coloured surface of the paper, said binder being adapted to retain the oily substance until released from the non-oily coating by pressure applied to the sheet material by the action of writing thereon, and a substantially white, opaque coating comprising precipitated calcium carbonate applied over the non-oily coating, the oily substance having approximately the same refractive index as precipitated calcium carbonate.

7. A process for manufacturing sheet material suitable for receiving and displaying written matter, which comprises the steps of providing oil-impervious paper with a coloured surface, applying over the coloured surface an adherent, substantially white, opaque coating comprising finely divided calcium carbonate in a form which is adapted to be rendered transparent thereby to allow the color of the paper surface to appear by the application to selected portions of the opaque coating of an oily substance having approximately the same refractive index as calcium carbonate and providing a coating of an oily substance of approximately the same refractive index as the opaque coating over the reverse surface of the oilimpervious paper.

8. A process for manufacturing sheet material suitable for receiving and displaying written matter which comprises the steps of providing paper with a coloured surface, applying an adherent, substantially white, opaque coating comprising finely-divided precipitated calcium carbonate dispersed in a binder selected from the group consisting of sodium alginate, gum arabic and adhesive cellulose derivatives to the coloured surface of the paper, said calcium carbonate coating being in a form which is adapted to be rendered transparent thereby to allow the color of the paper surface to appear by the application to selected portions of the opaque coating of an oily substance having approximately the same refractive index as calcium carbonate, applying an oil-impervious protective layer to the reverse surface of the paper and providing over the oil-impervious, protective layer a coating of an oily substance selected from the group consisting of oils, petroleum jelly, oils modified with a wax and oils modified with petroleum jelly applied to the oil-impervi- 7 rous layer, said Loily substance zhaving a refractive index substantially the same Vasthatof the opaque coating.

'9. ,A; process as claimed in claim 7 in which the opaque coating comprises finely-divided: precipitated calcium carbonatedispersed in a binder selected from thegroup consisting of sodium alginate, gum'arabic'and adhesive cellulose derivatives.

10. A process asclaimedin claim 7 which comprises including in the opaque coating comprising calcium car- .bonate asmall quantity of 1a substancehaving the colour of the desired writing.

'11. ,A process for manufacturing sheet material suitable for:receiving and displaying written matter which comprises the steps of providing paper with a coloured surface, applying to the coloured surface a coating of an oily substance, providing an oil-imperviousprotective layer over said coating of oily substance and applying to the oil-impervious protective layer an adherent, substantially rwhite opaque coating comprising finely-divided precipitated calcium carbonate in a form which is adapted to be rendered transparent thereby to allow the color of the .paper surface to appear by the application toselected portions of. the opaque coating ofan oily substance, hav- ,ing, approximately thesame refractive index as calcium carbonate.

12. A process for'manufacturing sheet material suitable for-receiving and displaying writtenmatter which comprises the steps of providing paper having a surface colouredother than white witha non-oily coating comprising discrete particles of an oily substance dispersed in' a binder applied to the coloured surface .of the paper, said binder being adapted, to retain the oily substance until released from the non-oily coating by pressure applied to the sheet material by the action of writing thereon, and .applying over the non-oily coating a substantially white, opaque coating comprising precipitated calcium carbonate,

, 8 .tliwi v s bstanc harinaapprq ima s -thesam jw astive indeX as precipitated calcium carbonate.

A P f prgus ss r t ma wnomh material comprising paper: having a coloured surface, '1-hih. nir s ma ghe salo rs Surface it a adherent, substantially white opaque coating comprising precipitated calcium carbonate and applyingan oily ,sub- ,stancehaving approximately the same refractive index as pi icipit z tedcalciumv carbonate to selected portionsof the opaqueCQatingto render, the coating transparent allow the colour of the coloured surface to appear in the form of written matter.

14. A process for producing writtenmatter on sheet .material cornprising, paper having a coloured surface,

References, Cited in the file of this patent UNITED STATES PATENTS 680,145 Hawley Aug. 6, 1901 1,374,112 wRafsky Apr.5, 1921 11,783,442 Mayer Dec. 2, 1930 1,936,286 Bradner Nov. 21, 1933 2,313,808 :Dalton Mar. 16, 1943 2,664,044 Dalton Dec. '29, 1953 12,668,126 Taylor Feb. 2,-1954 

1. SHEET MATERIAL SUITABLE FOR RECEIVING AND DISPLAYING WRITTEN MATTER WHICH COMPRISES OIL-IMPERVIOUS PAPER HAVING A COLOURED SURFACE UPON WHICH IS APPLIED AN ADHERENT, SUBSTANTIALLY WHITE, OPAQUE COATING COMPRISING FINELY-DIVIDED CALCIUM CARBONATE IN A FORM WHICH IS ADAPTED TO BE RENDERED TRANSPARENT THEREBY TO ALLOW THE COLOR OF THE PAPER SURFACE TO APPEAR BY THE APPLICATION TO SELECTED PORTIONS OF THE OPAQUE COATING OF AN OILY SUBSTANCE HAVING APPROXIMATELY THE SAME REFRACTIVE INDEX AS CALCIUM CARBONATE, SAID SHEET MATERIAL ALSO HAVING AN OILY SUBSTANCE OF APPROXIMATELY THE SAME REFRACTIVE INDEX AS THE OPAQUE COATING APPLIED TO THE REVERSE SURFACE. 